Snowmobiles are typically transported from place to place on trailers towed behind a vehicle. Specialized trailers have been devised specific to the task of transporting the snowmobile. One particular snowmobile trailer has a flat open bed with a hold down assembly attached near the front edge of the trailer bed to engage forward portions of the snowmobile runner assemblies. The hold down assembly includes brackets attached to either side of the trailer bed near the front edge. The brackets have aligned openings. A single hold down rod is trained through aligned openings of the brackets. The rod is spaced rearwardly of the leading edge of the trailer bed only a sufficient distance to enable engagement of structural components of the runner assembly of the snowmobile forward of the struts or legs that hold the runner assembly to the snowmobile body. The hold down rod is passed through the front portion of the runner assemblies of the snowmobile. The rod passes through openings in ribs attached to the top of the skis of the runner assembly and just above the ski surface. These hold down rod systems have the disadvantage of holding the snowmobile down to the trailer at a point that is very forward on the snowmobile and low on the trailer bed. These rod systems lack versatility. They rely upon the existence of correctly located openings in the runner assemblies.